Tilt adjustment mechanism for vehicle seat back, has opposing surface and one of two support surfaces of each blocking element rest slidably on control surface of cam and other support surface of adjacent blocking element

摘要

Each of four blocking elements (4) is provided an extension prolongation surrounding a cam disk (5). An opposing surface (4d) slidably rests on a control surface (5a) of the cam disk. A support surface (4c) of the blocking element rests slidably on another support surface (4b) formed by a recess (4f) of the adjacent blocking element. The cam disk is formed with four control surfaces equaling the number of blocking elements. An upper portion (1) and a lower portion (2) of the adjustment mechanism are mounted firmly on a seat back and a seat body respectively. Each blocking element is mounted between two guide surfaces (2a) slidably. An outer toothed surface (4a) of each blocking element engages an inner toothed surface (1a) concentric to a swivel axis (3) of the upper portion in the locked state. The blocking elements are radially displaced by the rotation of the cam disk, about the swivel axis. The cam disk is operated by through a link (6). The control surface is divided into a guide area (5c) and an eccentric area (5d). The control surfaces are separated by a recoil area (5b). A striking surface (4e) formed as an extension of the opposing surface, limits the rotation of the cam disk in one direction. The support surface (4c) is formed on the end of the blocking element facing away from the toothed surface. In the locked state, each blocking element rests on the guide area of one control surface and on the eccentric area of the adjacent control surface. The guide area is formed with a constant radius about the swivel axis and the eccentric area eccentric to the swivel axis. The end of the blocking element where the support surface is provided is formed conically tapered towards the outer toothed surface of the adjacent blocking element.